This invention relates to integration means, and more particularly to a device, added to a firearm and extending from the firearm's upper receiver over the firearm's barrel to the firearm's normal front sight position, for incorporating firearm ancillary equipment.
As the field of combat and commercial weaponry expands, numerous add-on enhancements have become available for attachment to standard firearms thereby significantly upgrading the capability of the firearm. Various methods and means have been developed for interfacing the various add-on enhancements to firearms. The Swan/Weaver rail described in U.S. Pat. No. 4,845,871, discloses a quickly detachable interface means for modular enhancements. Applicant's copending application, Ser. No. 07/763,966, now U.S. Pat. NO. 5,142,806 filed Sep. 23, 1991, incorporated herein by reference, discloses a universal receiver sleeve having an upper interface portion with standard, universal dimensions regardless of the firearm and having a lower interface portion specific to a particular firearm.
The above types of devices have a basic limitation because of their interface only to the firearm receiver's short length. Most standard firearms have a front, barrel mounted, "iron" sight for aiming. The front sight can interfere with the various enhancements interconnected to the receiver sleeve. Most standard firearms are also hand-held with two hands. The first hand generally holds the barrel portion of the firearm while the second hand holds the stock/pistol grip for activation of the firearm trigger. The first hand can also interfere with the various aiming enhancements interconnected to the receiver sleeve, and can deflect the point of aim due to hand pressure. Hand guards connected to the barrel can cause discomfort to the first hand due to overheated barrels in rapid fire. Unwanted heavy barrels are used to help retard barrel deflection and for heat retardation.